Pre-stressed laminated ski



Filed Aug. 8 ,1955

R T METCALFE ET AL PRE-SIRESSED LAMINATED SKI 7 Y JW w 1.. T u lL|L .M l- "n L {M Hli x. N m w\ m N rUnited States Patent PRE-STRESSED LAMINATED SKI Richard T. Metcalfe andEdrnond T. Chrobak, Ware,` Mass.

ApplicationiAugust 8, 1955,:SeriaLNo. 526,948

4 Claims. (Cl. 280-1'1L13) Our invention relates Vto new and.. useful improvements in a ski construction of the land or water type and is directed more particularly to the provision of a prestressed ski and to an improvement in the. means for producing same.

It is the principal object of our inventionto provide a novel and improved construction ofV the type in which certain components of the ski are stressed .or tensioned prior to assembly of the ski and there is the further provision of additional other innovationsin skis which will eliminate certain now present objectionable inconvenience and which will operate with a maximum amount of ease and with a. minimum degree of effort.

One of the primary purposes of our inventionis to provide structural and operational improvementsin devices of the class to which reference has been made, which improvements not only simplify the-structure as such but also provide important. distinct advantages in. strength, durability, efficiency andY the like.

As is well known, the ski throughout most of its length is slightly arched, so that without any weight applied thereto, ak small section of the ski. touches the plane at the rear and a small section touches the plane atthe front. When the weight of a skier is placed` on the ski, the ski is depressed so that it touches. continuouslyfrom front or upturn to rear or heel, thusA providing a depend able even support or uniform full bearing throughout the snow contacting length of the ski.

The stiffness of the spring preferably should gradually increase as the middle of the arch,y or footrest portion, gradually approaches the plane, so that the said middle portion does not pass below the horizontal plane. Any such sagging4 of the local section supporting the weight (i. e. the foot rest section) Vcreates a brake action and lessens the weight supporting bearing. This condition emphasizes theimportance of the ski retainingY the form initially imparted thereto.

In the utilizing of skis, it is highly desirablerthat the central part of the-ski be arched. Likewise it is desirable that this arch formation be maintained when the skis are not in use. The invention herein described offers means whereby the ski may be initially provided with the desired degree of arching prior to the complete fabrication of same, all to the end that the retention of the arched formation throughout the life of the ski is insured.

It is another object of our invention to provide a construction whereby the rigidity of the ski or the resistance thereof to longitudinal bowing maybe predetermined, it being readily understood and appreciated that varying degrees of exure are required for users of different weights.

It is still another object of the invention to provide a ski construction which is substantially uniformly ilexibl over its entire length.

Other prime objects of our invention include; first, the securement of a higher degree of accuracy and greater degree of variety in the manner of work performed therewith than has heretofore been possible with prior devices known in the art; second, the attainment of a higher speed ofzconstructionand assembly of thedevice due to its simpliiication of :design andl its uniquecomposition ofparts; third, the provision of an improved ski construction, which may be made more economically and with fewer operations'in the manufacture ofyits parts,v as well as in the assembly of the same, than prior devices known in the art; fourth, thel provision. of a construction which may be readily ,installed with respect tothe various purposes for whichit is intended, and-fth,1the provision of such other limprovements in and-relating to skiconstructions4 of the type above referred to as4 arehereinafter described and claimed.

With the above primary objects in View, it is another object of our invention to provide a construction of the above described character in which the number of operating partsis greatly reduced and which is compact in accordance with; the demands and desires of manufacturers and ,purchasers alike and which is not only distinctive in its appearance` and practical in its value but also reliable in its operation and efcient in its use.

Itl is a still further object tojprovide a device which is constructed of relativelysimple parts which are adapted to be readily assembled and which when once assembled are positively `and securely retained in operative relationship and which cannot bel readily separatedfromeach other.

Further objects and. advantages. of our invention will become .apparent-as the following `description proceeds, and the features of noveltywhich characterize the same will be pointed' outwithparticularity in the claims annexed to and forming part of `this specification.A

In the accompanying drawing, we have .illustrated a complete example of a physical embodimentV of the invention in which the parts. are combined andv arranged in accordance with one mode which we have devised for the practical application of the principles of the invention. It will however be understood` that changes and alterations are contemplated and may bemade in theseexemplifying drawings and mechanical structures, within the scope of the claims,without departngfrom the principles of the invention.

The above cited objects, We accomplish by means of such structure and relative arrangement of parts thereof as will fully appear by-a.per,us al of thedescription below and by various specific features which will be` hereinafter set forth.

To these ends, various, other and ancillary features and advantages andA objects of our invention willbecomefmore readily apparent asthe descriptionproceeds., Our invention consists in certain features of novelty, in amode. of operation, and inthe combination.. organization, and arrangement of partsas Willbehereinafter more Vparticularly pointed 'out in, the claims hereunto annexed and more fully described and referred .to inconjunctionwith the accompanying drawings wherein:

Fig.v 1 is, atop plan -view of a -ski .construction of1 the invention;

Fig. 2 is a side elevational view of the structure shown in Fig, l;

Fig.l 3 is an enlarged sectional elevational view on the line 3-3 .of Fig. l;

Fig. 4- is an enlarged sectional elevational View onthe line 4 4 of Fig. 1;

Fig. 5 is an enlargedsectional elevational View onthe line 5-5 of Fig. 1;

Fig. 6 is. an enlarged sectional elevational view on the line 6-6 of Fig. 1; and

Figs.` 7 and 8 are enlarged sectional elevational views showing modied'forms of Certain details of the construe,- tion of our invention.

In the above mentioned drawingannexed hereto and forming a part of this specification, we have presented but one general embodiment of the invention which is deemed preferable, but it is for purposes of illustration only. The invention is susceptable of incorporation in other modified forms coming equally within the scope of the claims hereof. Changes may be made in various respects and within the scope of the appended claims without departing from broad aspects and spirit of the invention.

In' the following description and claims, various details are identified by specific names for convenience. These names however are intended to be as generic in their application as the art will permit. Y

Referring now to the drawing more in detail, in which similar characters of reference indicate corresponding parts in the several figures and referring more particularly to the preferred form of my invention selected for illus ytrative purposes, we have shown a ski reinforcement con struction which comprises a forward metal toe plate member 2 and a rearward metal heel plate member 4. Same are held together in spaced relation by means of a pair of parallel spaced elongated runnerV or rail members 6 and 6 preferably of metal which are xed to the members 2 and 4 at their respective opposite ends, as shown, so as to form the general outline of a ski construction.

A`plurality of metallic pin or dowel members 8 are provided and connect the opposed runner members 6 and 6 at spaced points along the lengths thereof, as shown. They may be press fitted, threaded, or otherwise engaged as by screws or the like. Said members 8 function to strengthen the reinforcement construction and to hold the members 6 and 6 in the desired spaced relation.

A tensioning member which may be in the form of a high tensile strength steel wire 10 or the like is provided and'extends from the member 4 (where it is held in a manner shortly to be described) forwardly through suitable aligned openings 12 in the pin members 8 to a vertically disposed opening 14 in the member Zand is then returned through other aligned openings 12 in the pin members 8 back to the member 4.

Each free end of the member 10 is introduced to the member 4 through a vertically disposed conical or tapered opening 22 rearwardly of the forward face of the member 4, as best shown in Fig. 5.

A tapered plug member 24 is receivable in the opening 22 in such a manner that the tensioning member 10 may be led into the opening 22 and held adjacent the member 24, when the desired tension of the member 10 has been attained. The plug 24 is provided with a knurled surface and the plug may be forced upwardly into the open- Ving 22 securely so as to grip the extremity of the member 10 and to hold same. As the member 24 is moved upwardly, the member 10 is wedged in the opening so as to securely clamp the member 10 and prevent undesired movement thereof.

At the forward or toe plate 2, the member 10 is merely passed through the vertical opening 14 from the top to the bottom (or vice versa, as may be desired).

In any event, the construction is such that,by the pulling of the ends of the member 10 at the rearward end lof the device, the reinforcing structure may be caused to bow so as to produce the arched conguration aforementioned.

Such pulling amounts to pre-stressing and the same is accomplished until the desired degree of arching is 'attained whereat the plugs 24 are set into position so as to hold the ends of the member 10 secure relative to the heel plate whereby the arched configuration is retained.

Such pre-stressing having been attained, the remainder of the assembly of the ski may be accomplished. Y

Laminations of wood or the like comprising a top lamination 30 and a bottom vlamination `32 extend in the 'lateral direction of the ski so as to sandwich the forward plate member 2 and the rearward plate member 4 and so as to be disposed between the Yrunner or rail members 6 and 6, all as shown in Fig. 6.

Said laminations are ydisposed on opposite sides of (above and below) the pin members 8 so that air spaces 34 between the laminations are provided between each pair of pin members and the members 2 and 4. In this manner, the weight of the construction is lessened and the resiliency thereof is obviously enhanced.

Rivet members 38 may be provided, if desired, which extend vertically through the pin members 8 and through the laminations 30 and 32, as best shown in Fig. 3, so as to retain the components in their relative positions.

On the upper surface of the lamination 30 and on the lower surface of the lamination 32, layers of plastic 40 and 42 respectively may be disposed between the opposed members 6 and-6 and over the length of the ski from the forward tip of the toe plate to the rearward tip of the heel plate.

Same may be secured to the laminations 30 and 32 by any conventional bonding material. Y

If desired, the rail members 6 and 6 may be Vprovided with steel edges 50 on the lower sides thereof, which edges may be held in place by means of rivets 52 or the like extending through the adjacent member 6.

As modified forms of the construction, reference will now be made to Figs. 7 and 8.

In Fig. 7, each extremity of the member 10 is shown as being introduced to the member 4 through aligned openings 20 extending inwardly from the forward face of the member 4' and communicating with a conical or tapered verticallyrdisposed opening 22' rearwardly of the forward face.

A tapered plug member 24 is receivable in the opening 22 invsuch a manner that the tensioning member 10 may be led into the opening 22 and held adjacent the member 24', when the desired tension of the member 10 has been'attained.Y The plug 24 has a knurled surface `and may be forced upwardly into the opening so as to grip the extremity of the member 10 to hold same.

As the member 24' is moved upwardly, the member 10' is wedged in the opening so as to securely clamp the member 10' and prevent undesired movement thereof.

A vertically disposed opening 26' of a somewhat reduced diameter may be provided and may extend downwardly from the top of the member 4' so as to communicate with the opening 22'. When it is desired to remove the plug 24', same may be driven downwardly and outwardly by means of a tool which may be inserted through the opening 26. As another modified form of the feature of the invention, we have shown, in Fig. 8, an opening 22" in the plate member 4" which is conical in its configuration and tapers inwardly from the top face of the member 4".

4In this instance, a tapered plug 24 may be inserted downwardly so as to wedge a tensioning member 10" extending inwardly into the opening 22" from the vforward face of the member 4" as shown. v

In any event, the construction is such that by the pulling of the ends of the member 10' or 10" at the rearward Yeudof the device, the reinforcing structure may be caused to bow so as to produce the arched configuration aforementioned.

When the desired degree of arching is attained, the plugs 24' or 24" are set into position so as to hold the ends of the members 10' or 10 `respectively secure relative to the structure whereby the arched configuration is retained. Such pre-stressing having been attained, the remainder of the assembly of the ski may be accomplished.

In the modiiication shown in Fig. 7, Vtop and bottom laminations 30 and 32 are disposed between rails 6 (as in Fig. 6) and abut member 4. In the modification 'shown in Fig. 8, similar laminations 30 and 32 are disposed between rails 6 (as in Fig. 6) and abut member 14".

While we have illustrated and described the invention as embodied in a specific arrangement, we do not intend to belimited to the details shown since various modiu cations and structural changes may be made without departing in any way from the spirit of the invention. Without further analysis, the foregoing is intended to so fully reveal the gist of our invention that others can, by applying current knowledge, readily adapt it to various applications without omitting features which, from the standpoint of prior art, fairly constitute essential characteristics of the generic aspects of this invention, and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims below.

What it is desired to claim and secure by Letters Patent of the United States is:

l. Ski construction comprising in combination, metallic toe and heel plates, elongated metallic runners having opposite ends secured to said toe and heel plates and having inner sides spaced apart `transversely between said toe and heel plates, a plurality of dowels relatively spaced along said runners intermediate upper and lower sides thereof and having opposite ends connected to inner sides of said runners, elongated laminations disposed between inner longitudinal sides of said runners rand extending over said plates and above and below said dowels providing elongated air spaces between inner adjacent faces thereof and the inner ends of said plates, said dowels provided with openings therethrough for tension wires, and elongated wires extending along the air spaces and through the openings in said dowels and being connected to said toe and heel plates so as to be under tension to bow the ski slightly upwardly from the lower side thereof between said toe and heel plates.

2. Ski construction comprising in combination, toe and heel plates, elongated spaced runners having opposite ends secured to adjacent inner ends of said toe and heel plates, a plurality of dowels relatively spaced along and between said runners intermediate upper and lower sides thereof, elongated strips of laminations disposed between inner longitudinal sides of the runners and extending over said toe and heel plates and above and below said dowels providing elongated air spaces between inner adjacent faces thereof and the inner ends of said toe and heel plates, said dowels being provided with openings therethrough, and an elongated wire extending along the air spaces and through the openings in said dowels and being connected to said toe and heel plates for tensioning to bow the ski slightly upwardly from the lower side thereof between said toe and heel plates.

3. A prestressed ski construction comprising, spaced metallic toe and heel plates, spaced elongated metallic runners having opposite ends secured to said toe and heel plates, a plurality of dowels relatively spaced between said runners and having opposite ends connected to said runners, said dowels being provided with openings therethrough, an elongated tensioning wire extending through the openings in said dowels and connected to said toe and heel plates for the bowing of said runners between said toe and heel plates, and elongated laminations disposed between inner longitudinal sides of said runners and above and below said dowels and extending over and under said toe and heel plates.

4, A prestressed ski construction comprising in combination, spaced toe and heel plates, spaced elongated runners having opposite ends secured to adjacent inner ends of said toe and heel plates, a plurality of apertured dowels relatively spaced between said runners intermediate upper and lower sides thereof, lan elongated tension wire extending through the apertures in said dowels and being connected to said toe and heel plates for the flexing of said runners between said toe and heel plates, and elongated strips of lamination disposed between inner sides of said runners in their stressed condition and extending over said toe and heel plates and above and below said dowels.

References Cited in the le of this patent UNITED STATES PATENTS 2,188,582 Serr Jan. 30, 1940 2,258,046 Clement Oct. 7, 1941 2,539,224 Beerli Jan. 23, 1951 FOREIGN PATENTS 927,897 France May 19, 1947 

